Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cb2e4c781f0dca3…

MALICIOUS

PDF

80.2 KB Created: 2021-09-17 16:13:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3650591523f579be8da642b2c3cd4f40 SHA-1: 80bd1f35da041e38a1498029473d0f0092b170e9 SHA-256: 4cb2e4c781f0dca3dd56e0a976e915c795057c88d4564b3911bd5ab2331d138c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to potentially malicious domains, and exhibits characteristics of a link farm. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/lowikufikukegu.pdf In PDF document text
    • http://ed-web.cz/userfilesfile/7657542467.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/66610108035.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614371d0dec06---74238919645.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/53209516199.pdfIn PDF document text
    • http://egitara.com/upfiles/files/fanunefit.pdfIn PDF document text
    • http://paraglider24.de/pics/fotos/1/file/65367753909.pdfIn PDF document text
    • https://camerabentrenet.camerabentre.vn/ckfinder/userfiles/files/lunosajovifexibomirula.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16130f22b021dc---84624087714.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/25031675237.pdfIn PDF document text
    • http://pspectr.ru/userfiles/file/folavizulajenejugezugofa.pdfIn PDF document text
    • http://xn--2e0b30g3uq7pay7m.com/upload/fckeditor/file/70791076880.pdfIn PDF document text
    • https://phongkhamtamthan.net/uploadeditor/files/dejuwi.pdfIn PDF document text
    • https://bnbcostaverde.it/userfiles/file/jowobusifaxaki.pdfIn PDF document text
    • http://imhome-listings.com/userfiles/files/58291414997.pdfIn PDF document text
    • http://fslawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/66292947873.pdfIn PDF document text
    • http://noticiascgnews.com.br/ckfinder/userfiles/files/vukevamezutegikibarur.pdfIn PDF document text
    • https://derya.afmiletisimajansi.info/resimler/files/19896344676.pdfIn PDF document text
    • http://kozhencherrymtc.org/userfiles/file/mimisopeximufinarorux.pdfIn PDF document text
    • http://hawaii-resort.info/images/blog/file/16807085257.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/18238105592.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/mineloj.pdfIn PDF document text
    • http://kronospan-mofa-hungary.hu/editor_up/nafapijabozufokikotoraba.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613e075a9bd9e---fufum.pdfIn PDF document text
    • http://sbstroy53.ru/img/files/10496510920.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=formula+of+half+circle+areaPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d631.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD631 17808 bytes
SHA-256: eda2aeabf42eeddec9892e4241dc05b8a3b1d1ced4b31cfeccb940280234a7f1
font_01_sfnt_off00010458.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10458 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6F 10308 bytes
SHA-256: 4f44c6d8ffa57735ba16a15ee9abb9b8bd816d9fc4257310d10f7571f62a4bf5